Highlighting Multiple Lines of Text in IOS 26?

I'm having this same issue and Microsoft Support has recommended getting support from Apple (https://learn.microsoft.com/en-us/answers/questions/5761304/unable-to-highlight-text-to-copy-on-ipad-air-13-on). Here's what they said "Since the issue reproduces across different accounts on the same device and persists outside of drawing mode, this points to a broader iOS level text selection or gesture handling impact that can affect app interactions. For that reason, the most effective next action is to submit feedback through the Apple Community or Apple’s feedback channels so the iOS team can review and track the behavior. This is the most effective way to ensure your voice reaches the product team and can be considered about how company-only contacts are handled in search results, with potential improvements being considered for future improvements.  

When submitting your feedback, please include that you are using an iPad Air 13, that the issue occurs in OneNote while on the Home tab (not Draw), and that it reproduces on both a work account and a personal account."

Well, it’s not widespread on my iPhone, it works as it should, and I haven’t seen any other posts about it.

You should try restarting your iPhone.

Tap and hold a word, then drag the handle.